Elxsi
Encyclopedia
Elxsi was a minicomputer
manufacturing company established in the late 1970s along with a host of other competitors (Trilogy Systems
, Sequent
, Convex Computer
). The Elxsi processor was an Emitter Coupled Logic
(ECL) design that featured a 50 nanosecond clock, a 25 nanosecond backpanel bus, IEEE floating point arithmetic and a 64-bit
architecture. It allowed multiple processors to communicate over a common bus called the Gigabus. The operating system
was a message based operating system called EMBOS. The Elxsi CPU was a microcode
d design, allowing custom instructions to be coded into microcode.
. Much of the architecture of the Elxsi machine was designed by former Stanford University professors Len Shar and Balasubrimanian Kumar. Another key contributor to the design was Harold (Mac) McFarland, who was also a key designer on the team that created the PDP-11
. George Taylor (on the IEEE standard committee and a student of Cal Berkeley Professor William Kahan
) provided a key design for the IEEE floating point unit. Elxsi was bought out by Gene Amdahl
with money that was left over from the Trilogy venture.
Venture investors in Elxsi included Tata Group
(India) and Arthur Rock
. In the early 1990s, however, Elxsi went out of business because of the general shift away from the use of mainframes in the global computer industry and the advent of the personal computer. The Tata Group
kept the name Tata Elxsi
but it now belongs to the Tata group of companies.
The large range of hardware expansion gave the machine some success in departmental technical computing environments. The 64-bit registers and ability to do parallel adds within them gave it an unanticipated advantage in COBOL
benchmarks, where it outperformed some mainframes. And the extreme independence of the CPUs (lack of cache snooping and invalidation), coupled with the ability to lock processes into register sets and later, the ability to partition the caches, gave it some success in real time applications.
: a category of computers that was larger than a VAX
11/780 and smaller than a mainframe
. This market segment disappeared as high end microprocessor based systems became more powerful.
The architecture was unusual, especially for its day. The system bus connected as many as 12 CPUs and I/O processors. Each CPU was built from 3 large boards of ECL gate arrays. Key elements of its instruction set architecture were:
. It was a multi-server architecture (like GNU Hurd
, but long predating that project). The UI was Unix
-like, especially at the shell level, with similar concepts but different commands, syntax, etc. (e.g. "files" instead of "ls"; "find" instead of "grep"). Later, a Unix kernel was hosted on top of the lower-level servers so that EMBOS and Unix processes and users could co-exist (ENIX). VMS
compatibility software running on top of EMBOS was also added to ease porting of VAX
applications.
Minicomputer
A minicomputer is a class of multi-user computers that lies in the middle range of the computing spectrum, in between the largest multi-user systems and the smallest single-user systems...
manufacturing company established in the late 1970s along with a host of other competitors (Trilogy Systems
Trilogy Systems
Trilogy Systems Corporation was a computer systems company started in 1980. Originally called ACSYS, the company was founded by Gene Amdahl, his son Carl Amdahl and Clifford Madden. Flush with the success of his previous company, Amdahl Corporation, Gene Amdahl was able to raise $230 million for...
, Sequent
Sequent Computer Systems
Sequent Computer Systems, or Sequent, was a computer company that designed and manufactured multiprocessing computer systems. They were among the pioneers in high-performance symmetric multiprocessing open systems, innovating in both hardware and software Sequent Computer Systems, or Sequent, was...
, Convex Computer
Convex Computer
Convex Computer Corporation was a company that developed, manufactured and marketed vector minisupercomputers and supercomputers for small-to-medium-sized businesses. Their later Exemplar series of parallel computing machines were based on the Hewlett-Packard PA-RISC microprocessors, and in 1995,...
). The Elxsi processor was an Emitter Coupled Logic
Emitter coupled logic
In electronics, emitter-coupled logic , is a logic family that achieves high speed by using an overdriven BJT differential amplifier with single-ended input, whose emitter current is limited to avoid the slow saturation region of transistor operation....
(ECL) design that featured a 50 nanosecond clock, a 25 nanosecond backpanel bus, IEEE floating point arithmetic and a 64-bit
64-bit
64-bit is a word size that defines certain classes of computer architecture, buses, memory and CPUs, and by extension the software that runs on them. 64-bit CPUs have existed in supercomputers since the 1970s and in RISC-based workstations and servers since the early 1990s...
architecture. It allowed multiple processors to communicate over a common bus called the Gigabus. The operating system
Operating system
An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...
was a message based operating system called EMBOS. The Elxsi CPU was a microcode
Microcode
Microcode is a layer of hardware-level instructions and/or data structures involved in the implementation of higher level machine code instructions in many computers and other processors; it resides in special high-speed memory and translates machine instructions into sequences of detailed...
d design, allowing custom instructions to be coded into microcode.
History
Elxsi was founded in 1979 by Joe Rizzi who had been a manager at IntersilIntersil
Intersil Corporation is an American company that specializes in the design, development and manufacturing of high-performance analog semiconductors for four high-growth markets — Communications, Computing, High End Consumer and Industrial.-Company history:...
. Much of the architecture of the Elxsi machine was designed by former Stanford University professors Len Shar and Balasubrimanian Kumar. Another key contributor to the design was Harold (Mac) McFarland, who was also a key designer on the team that created the PDP-11
PDP-11
The PDP-11 was a series of 16-bit minicomputers sold by Digital Equipment Corporation from 1970 into the 1990s, one of a succession of products in the PDP series. The PDP-11 replaced the PDP-8 in many real-time applications, although both product lines lived in parallel for more than 10 years...
. George Taylor (on the IEEE standard committee and a student of Cal Berkeley Professor William Kahan
William Kahan
William Morton Kahan is a mathematician and computer scientist who received the Turing Award in 1989 for "his fundamental contributions to numerical analysis", and was named an ACM Fellow in 1994....
) provided a key design for the IEEE floating point unit. Elxsi was bought out by Gene Amdahl
Gene Amdahl
Gene Myron Amdahl is a Norwegian-American computer architect and high-tech entrepreneur, chiefly known for his work on mainframe computers at IBM and later his own companies, especially Amdahl Corporation...
with money that was left over from the Trilogy venture.
Venture investors in Elxsi included Tata Group
Tata Group
Tata Group is an Indian multinational conglomerate company headquartered in Mumbai, Maharashtra, India. Tata Group is one of the largest companies in India by market capitalization and revenue. It has interests in communications and information technology, engineering, materials, services, energy,...
(India) and Arthur Rock
Arthur Rock
Arthur Rock is an American venture capitalist of Silicon Valley, California. He was an early investor in major firms including Intel, Apple Computer, Scientific Data Systems and Teledyne....
. In the early 1990s, however, Elxsi went out of business because of the general shift away from the use of mainframes in the global computer industry and the advent of the personal computer. The Tata Group
Tata Group
Tata Group is an Indian multinational conglomerate company headquartered in Mumbai, Maharashtra, India. Tata Group is one of the largest companies in India by market capitalization and revenue. It has interests in communications and information technology, engineering, materials, services, energy,...
kept the name Tata Elxsi
Tata elxsi
- Introduction : is a technology-led design services company and part of the $70 billion Tata Group. Headquartered in Bangalore and with a global delivery footprint through offices and centers in India, the US, the UK, Japan and Germany, Tata Elxsi is a company focused on delivering outsourced...
but it now belongs to the Tata group of companies.
The large range of hardware expansion gave the machine some success in departmental technical computing environments. The 64-bit registers and ability to do parallel adds within them gave it an unanticipated advantage in COBOL
COBOL
COBOL is one of the oldest programming languages. Its name is an acronym for COmmon Business-Oriented Language, defining its primary domain in business, finance, and administrative systems for companies and governments....
benchmarks, where it outperformed some mainframes. And the extreme independence of the CPUs (lack of cache snooping and invalidation), coupled with the ability to lock processes into register sets and later, the ability to partition the caches, gave it some success in real time applications.
Hardware
The Elxsi machine was a mini-supercomputerMinisupercomputer
Minisupercomputers constituted a short-lived class of computers that emerged in the mid-1980s. As scientific computing using vector processors became more popular, the need for lower-cost systems that might be used at the departmental level instead of the corporate level created an opportunity for...
: a category of computers that was larger than a VAX
VAX
VAX was an instruction set architecture developed by Digital Equipment Corporation in the mid-1970s. A 32-bit complex instruction set computer ISA, it was designed to extend or replace DEC's various Programmed Data Processor ISAs...
11/780 and smaller than a mainframe
Mainframe computer
Mainframes are powerful computers used primarily by corporate and governmental organizations for critical applications, bulk data processing such as census, industry and consumer statistics, enterprise resource planning, and financial transaction processing.The term originally referred to the...
. This market segment disappeared as high end microprocessor based systems became more powerful.
The architecture was unusual, especially for its day. The system bus connected as many as 12 CPUs and I/O processors. Each CPU was built from 3 large boards of ECL gate arrays. Key elements of its instruction set architecture were:
- 16 registers (64-bit64-bit64-bit is a word size that defines certain classes of computer architecture, buses, memory and CPUs, and by extension the software that runs on them. 64-bit CPUs have existed in supercomputers since the 1970s and in RISC-based workstations and servers since the early 1990s...
) - 32-bit32-bitThe range of integer values that can be stored in 32 bits is 0 through 4,294,967,295. Hence, a processor with 32-bit memory addresses can directly access 4 GB of byte-addressable memory....
linear address space (64-bit integers but 32-bit pointers) - Multiple register sets per processor, with switches among processes loaded into register sets handled by microcode
- Small set of basic addressing modes
- Small set of instruction lengths, length determinable from first few nibbles of instruction
- No hardware cache coherence among processors
- Microcoded message system to communicate among software processes and with I/O controllers and CPU microcode
- No supervisor mode—equivalent restrictions applied by controlling which processes held special message system communication links and which virtual address space had the memory management tables mapped into it
- Two generations of CPU were sold and a third developed but never sold. All plugged into the same backplane and could be intermixed in a single system.
Software
The EMBOS OS was written entirely from scratch in a slightly extended PascalPascal (programming language)
Pascal is an influential imperative and procedural programming language, designed in 1968/9 and published in 1970 by Niklaus Wirth as a small and efficient language intended to encourage good programming practices using structured programming and data structuring.A derivative known as Object Pascal...
. It was a multi-server architecture (like GNU Hurd
GNU Hurd
GNU Hurd is a free software Unix-like replacement for the Unix kernel, released under the GNU General Public License. It has been under development since 1990 by the GNU Project of the Free Software Foundation...
, but long predating that project). The UI was Unix
Unix
Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...
-like, especially at the shell level, with similar concepts but different commands, syntax, etc. (e.g. "files" instead of "ls"; "find" instead of "grep"). Later, a Unix kernel was hosted on top of the lower-level servers so that EMBOS and Unix processes and users could co-exist (ENIX). VMS
OpenVMS
OpenVMS , previously known as VAX-11/VMS, VAX/VMS or VMS, is a computer server operating system that runs on VAX, Alpha and Itanium-based families of computers. Contrary to what its name suggests, OpenVMS is not open source software; however, the source listings are available for purchase...
compatibility software running on top of EMBOS was also added to ease porting of VAX
VAX
VAX was an instruction set architecture developed by Digital Equipment Corporation in the mid-1970s. A 32-bit complex instruction set computer ISA, it was designed to extend or replace DEC's various Programmed Data Processor ISAs...
applications.
Famous employees
Although Elxsi was not a financial success, many of its employees did go on to fame and fortune.- Ralph MerkleRalph MerkleRalph C. Merkle is a researcher in public key cryptography, and more recently a researcher and speaker on molecular nanotechnology and cryonics...
(who wrote the Elxsi FortranFortranFortran is a general-purpose, procedural, imperative programming language that is especially suited to numeric computation and scientific computing...
compilerCompilerA compiler is a computer program that transforms source code written in a programming language into another computer language...
) later became a noted nanotechnologist. - Rob Catlin became an early employee of Chips and TechnologiesChips and TechnologiesChips and Technologies was the first fabless semiconductor company, a model developed by its founder Gordon Campbell. Founded by Dado Banatao.Its first product was an EGA IBM compatible graphics chip...
. - Thampy Thomas became a founder of NexGenNexGenNexGen was a private semiconductor company that designed x86 microprocessors until it was purchased by AMD in 1996.Like competitor Cyrix, NexGen was a fabless design house that designed its chips but relied on other companies for production...
, which was later acquired by AMDAdvanced Micro DevicesAdvanced Micro Devices, Inc. or AMD is an American multinational semiconductor company based in Sunnyvale, California, that develops computer processors and related technologies for commercial and consumer markets...
. The NexGenNexGenNexGen was a private semiconductor company that designed x86 microprocessors until it was purchased by AMD in 1996.Like competitor Cyrix, NexGen was a fabless design house that designed its chips but relied on other companies for production...
design became the design for the AMD K6AMD K6The K6 microprocessor was launched by AMD in 1997. The main advantage of this particular microprocessor is that it was designed to fit into existing desktop designs for Pentium branded CPUs. It was marketed as a product which could perform as well as its Intel Pentium II equivalent but at a...
processor. - Mac McFarland was also an early NexGen employee. Mac's role in the design of the PDP-11PDP-11The PDP-11 was a series of 16-bit minicomputers sold by Digital Equipment Corporation from 1970 into the 1990s, one of a succession of products in the PDP series. The PDP-11 replaced the PDP-8 in many real-time applications, although both product lines lived in parallel for more than 10 years...
is given in Gordon Bell's history of DECDigital Equipment CorporationDigital Equipment Corporation was a major American company in the computer industry and a leading vendor of computer systems, software and peripherals from the 1960s to the 1990s...
(page 87) http://research.microsoft.com/~gbell/Digital/Digital%20at%20work%201992.pdf - B. V. Jagadeesh became a founder of Exodus CommunicationsExodus CommunicationsExodus Communications was an Internet hosting service and Internet service provider to dot-com businesses. It went broke, along with many of its customers, during the bursting of the dot-com bubble. It declared Chapter 11 bankruptcy in 2001 and was purchased by Cable and Wireless in November...
took it public in 1998 and became CEO of NetScaler in Aug 2000 and successfully sold to Citrix for $325M in 2005 - Bob RauBob RauBantwal Ramakrishna "Bob" Rau was a computer engineer. Rau was a founder and chief architect of Cydrome, where he helped develop the Very long instruction word technology that is now standard in modern computer processors. Rau was the recipient of the 2002 Eckert–Mauchly Award.-External links:* *...
and Arun Kumar became founders of CydromeCydromeCydrome was a computer company started in 1984 in San Jose, California whose mission was to develop a numeric processor. The founders were David Yen, Wei Yen, Ross Towle, Arun Kumar, and Bob Rau...
. Bob then worked at HP Labs and was one of the developers of the IA-64 architecture. http://www.hpl.hp.com/news/2001/apr-jun/itanium.html#scientists - Allen Roberts and Harlan Lau became early employees of RambusRambusRambus Incorporated , founded in 1990, is a technology licensing company. The company became well known for its intellectual property based litigation following the introduction of DDR-SDRAM memory.- History :...
- John Sanguinetti founded Chronologic and wrote the VCS VerilogVerilogIn the semiconductor and electronic design industry, Verilog is a hardware description language used to model electronic systems. Verilog HDL, not to be confused with VHDL , is most commonly used in the design, verification, and implementation of digital logic chips at the register-transfer level...
Compilerhttp://www.aycinena.com/index2/index3/archive/john%20sanguinetti.html - Robert Olson became the founder of Virtual Vineyards (now wine.com), and later served as an engineering executive with several Internet-focused startups, such as PostX (http://www.postx.com).
- Mike FarmwaldMike FarmwaldMike Farmwald is a successful serial entrepreneur working in the Silicon Valley high-tech industry.Mike Farmwald is known for his combination of computer engineering skill and market vision...
(an Elxsi consultant) founded several Silicon ValleySilicon ValleySilicon Valley is a term which refers to the southern part of the San Francisco Bay Area in Northern California in the United States. The region is home to many of the world's largest technology corporations...
high tech companies. - Jim Kaschmitter is the CEO of UltraCell, a maker of micro fuel cells
- Sha-shu Lin was a founder at iPlanetIPlanetiPlanet was a product brand that was used jointly by Sun Microsystems and Netscape Communications Corporation when delivering software and services as part of a non-exclusive cross marketing deal that was also known as "A Sun|Netscape Alliance"....
and is now VP of Eilinkhttp://www.zoominfo.com/people/Lin_Sha-Shu_34246264.aspx - Kevin McGrath is an AMD Fellow and developed the 64 bit extensions for the AMD64 architecture.
- Russell Williams is an architect and engineer of Adobe SystemsAdobe SystemsAdobe Systems Incorporated is an American computer software company founded in 1982 and headquartered in San Jose, California, United States...
Photoshop - Loren KohnfelderLoren KohnfelderLoren Kohnfelder is best known for his MIT S.B. thesis written in May 1978 describing a practical means of applying public key cryptography to secure network communications....
originated the idea of the digital certificate and developed security for the Microsoft Internet Explorer. - Herbert (Bert) Slade, Vice President of Field Service